<?php
session_start();
require("../configuration.php");
$login=$_POST['login'];
		
		$check_res = mysql_query("SELECT u_login FROM users");
		$num = mysql_num_rows($check_res);
		$b=true;
		for($i=0;$i<$num;$i++){
			$res=mysql_fetch_row($check_res);
			if($res[0]==$login){$b=false;}
		}
		
		if($b==true){echo "yes";}
		else{echo "no";}
		
?>